Two distinct retroviruses, human immunodeficiency virus (HIV) type-1 (HIV-1) or type-2 (HIV-2), have been etiologically linked to the immunosuppressive disease, acquired immunodeficiency syndrome (AIDS). HIV seropositive individuals are initially asymptomatic but typically develop AIDS related complex (ARC) followed by AIDS. Affected individuals exhibit severe immunosuppression, which predisposes them to debilitating and ultimately fatal opportunistic infections.
The disease AIDS is the end result of an HIV-1 or HIV-2 virus following its own complex life cycle. The virion life cycle begins with the virion attaching itself to the host human T-4 lymphocyte immune cell through the bonding of a glycoprotein on the surface of the virion's protective coat with the CD4 glycoprotein on the lymphocyte cell. Once attached, the virion sheds its glycoprotein coat, penetrates into the membrane of the host cell, and uncoats its RNA. The virion enzyme, reverse transcriptase, directs the process of transcribing the RNA into single-stranded DNA. The viral RNA is degraded and a second DNA strand is created. The now double-stranded DNA is integrated into the human cell's genes and those genes are used for virus reproduction.
At this point, RNA polymerase transcribes the integrated DNA into viral RNA. The viral RNA is translated into the precursor gag-pol fusion polyprotein, the polyprotein is then cleaved by the HIV protease enzyme to yield the mature viral proteins. Thus, HIV protease is responsible for regulating a cascade of cleavage events that lead to the virus particle's maturing into a virus that is capable of full infectivity.
The typical human immune system response, killing the invading virion, is taxed because the virus infects and kills the immune system's T cells. In addition, viral reverse transcriptase, the enzyme used in making a new virion particle, is not very specific, and causes transcription mistakes that result in continually changed glycoproteins on the surface of the viral protective coat. This lack of specificity decreases the immune system's effectiveness because antibodies specifically produced against one glycoprotein may be useless against another, hence reducing the number of antibodies available to fight the virus. The virus continues to reproduce while the immune response system continues to weaken. Eventually, the HIV largely holds free reign over the body's immune system, allowing opportunistic infections to set in and without the administration of antiviral agents, immunomodulators, or both, death may result.
There are at least three critical points in the virus's life cycle which have been identified as possible targets for antiviral drugs: (1) the initial attachment of the virion to the T-4 lymphocyte or macrophage site, (2) the transcription of viral RNA to viral DNA (reverse transcriptase, RT), and (3) the processing of gag-pol protein by HIV protease.
The genomes of retroviruses encode a protease that is responsible for the proteolytic processing of one or more polyprotein precursors such as the pol and gag gene products. Retroviral proteases most commonly process the gag precursor into the core proteins, and also process the pol precursor into reverse transcriptase and retroviral protease. The correct processing of the precursor polyproteins by the retroviral protease is necessary for the assembly of the infectious virions. It has been shown that in vitro mutagenesis that produces protease-defective virus leads to the production of immature core forms which lack infectivity. Therefore, retroviral protease inhibition provides an attractive target for antiviral therapy.
As evidenced by the protease inhibitors presently marketed and in clinical trials, a wide variety of compounds have been studied as potential HIV protease inhibitors. The first inhibitor of so-called retroviral aspartate protease to be approved for combating the infection was saquinavir. Since then others have followed including indinavir (Merck), ritonavir (Abbott), amprenavir and its prodrug amprenavir phosphate (Vertex/GSK), lopinavir (Abbott), nelfinavir (Aguoron/Pfizer), tipranavir (Pharmacia/Boehringer) and atazanavir (Novartis/BMS).
Each of these prior art compounds has liabilities in the therapeutic context resulting in sub-optimal treatment regimes, side effects such as lipodystrophy and poor patient compliance. In conjunction with the replicative infidelity of the HIV genetic machinery and the very high viral turnover in vivo, the sub-optimal performance and pharmacokinetics of prior art HIV protease inhibitors enable the rapid generation of drug escape mutants. This in turn dramatically limits the effective treatment length of current HIV drugs as HIV quickly becomes resistant and/or patients develop physical or psychological aversions to the drugs themselves or their side effects.
The aim of the present invention is to provide a novel type of compound that is equipped, especially, with a high degree of inhibitory activity against virus replication in cells, high antiviral activity against numerous virus strains, including those which are resistant to known compounds, such as saquinavir, ritonavir and indinavir, and especially advantageous pharmacological properties, for example good pharmacokinetics, such as high bioavailability and high blood levels, and/or high selectivity.
In accordance with the invention, there is provided a compound of the formula I:
wherein
R1 is —R1′, —OR1′, —SR1′,
R1′ is C1-C6Alk, C0-C3alkanediylcarbocyclyl or C0-3alkanediylheterocyclyl, any of which is optionally substituted with up to 3 substituents independently selected from R10;
R2 is C1-C6Alk, C0-C3alkanediylcarbocyclyl, C0-C3alkanediylheterocyclyl, any of which is optionally substituted with up to 3 substituents independently selected from R10;
X is H, F, OH, C1-C3Alk or C0-C3alkanediyl-O—C1-C3alkyl;
L is OH, F, NH2, —NHC1-C3Alk; —N(C1-C3Alk)2;
n is 0, 1 or 2;
E is N or CH;
A′ is a bicyclic ring system comprising a first 5 or 6 membered saturated ring optionally containing an oxygen hetero atom and optionally substituted with hydroxy and/or methyl, having fused thereto a second 5 or 6 membered unsaturated ring optionally containing one or two hetero atoms selected from S, O and N, and optionally substituted with mono- or di-fluoro; or
A′ is a group of formula (II), (II′), (III) or (IV):
wherein,
R3 is H; or R3 is C1-C6Alk, C0-C3alkanediylcarbocyclyl, C0-C3alkanediylheterocyclyl, any of which is optionally substituted with up to three substituents independently selected from R11;
R4 is C1-C6Alk, C0-C3alkanediylcarbocyclyl, C0-C3alkanediylheterocyclyl, any of which is optionally substituted with up to three substituents independently selected from R10;
R5 is C1-C6Alk, C0-C3alkanediylcarbocyclyl, C0-C3alkanediylheterocyclyl, any of which is optionally substituted with up to three substituents independently selected from R10;
Z is a bond, —NH— or —O—;
Rx is H, C1-C3alkyloxy, C1-C3 straight or branched alkyl optionally substituted with halo, hydroxy, C1-C3alkyloxy; or Rx, together with the adjacent carbon atom, defines a fused furanyl or pyranyl ring which is optionally substituted with halo or C1-C3Alk;
t is 0 or 1;
A″ is a group of formula (V), (VI) (VII) or (VIII);
wherein;
R8 is H; or R8 is C1-C6Alk, C0-C3alkanediylcarbocyclyl, C0-3alkanediylheterocyclyl, any which is optionally substituted with up to three substituents independently selected from R11 
R9 is C1-C6Alk, C0-C3alkanediylcarbocyclyl, C0-3alkanediylheterocyclyl, any of which is optionally substituted with up to three substituents independently selected from R10;
W is a bond, —NR13— or —O—;
R13 is H, C1-C6Alk or R13 and R9 together with the N atom to which they are attached define a saturated, partially saturated or aromatic N-containing ring containing 5 or 6 ring atoms, which is optionally substituted with up to three substituents selected from R10;
D is O or NH;
Ry is H or Ry, together with the adjacent C atom defines a fused furan or pyran ring;
Q is O, CHR8 or a bond;
R15 is carbocyclyl or heterocyclyl, any of which is optionally substituted with up to three substituents independently selected from C1-C3Alk, hydroxy, oxo, halo;
r and q are independently 0 or 1;
R10 is halo, oxo, cyano, azido, nitro, C1-C6Alk, C0-C3alkanediylcarbocyclyl, C0-C3alkanediylheterocyclyl, Y—NRaRb, Y—O—Rb, Y—C(═O)Rb, Y—(C═O)NRaRb, Y—NRaC(═O)Rb, Y—NHSOpRb, Y—S(═O)pRb, Y—S(═O)pNRaRb, Y—C(═O)ORb or Y—NRaC(═O)ORb; wherein;
Y is a bond or C1-C3alkanediyl;
Ra is H or C1-C3Alk;
Rb is H or C1-C6Alk, C0-C3alkanediylcarbocyclyl or C0-C3alkanediylheterocyclyl;
p is 1 or 2;
R11 is halo, oxo, cyano, azido, nitro, C1-C3Alk, Y—NRaRa′, Y—O—Ra; wherein;
Ra′ is H or C1-C3Alk; or Ra and Ra′ and the nitrogen atom to which they are attached define pyrrolidine, morpholine, piperidine or piperazine which is optionally 4-substituted with methyl or acetyl;
and pharmaceutically acceptable salts thereof.
A further aspect of the invention embraces a pharmaceutical composition comprising a compound as defined above and a pharmaceutically acceptable carrier or diluent therefore. A still further aspect of the invention envisages the use of a compound as defined above in the manufacture of a medicament for the prophylaxis or treatment of HIV infection. An additional aspect of the invention provides a method of medical treatment or prophylaxis for HIV infection comprising the administration of an effective amount of a compound as defined in above to an individual infected or threatened with HIV infection.
Without in any way wishing to be bound by theory, or the ascription of tentative binding modes for specific variables, the notional concepts P1, P1′, P2 and P2′ as used herein are provided for convenience only and have substantially their conventional meanings, as illustrated by Schechter & Berger, (1976) Biochem Biophys Res Comm 27 157-162, and denote those portions of the inhibitor believed to fill the S1, S1′, S2 and S2′ subsites respectively of the enzyme, where S1 is adjacent and S2 remote from the cleavage site on one side and S1′ is adjacent and S2′ remote from the cleavage site on the other side. Regardless of binding mode, the compounds defined by Formula I are intended to be within the scope of the invention. It is conceivable that R1 and R2 respectively fill the S1 and S1′ subsites, whereas A′ and A″ interact with the S2 and S2′, but also conceivable with the inverse arrangement.
Conveniently, the compounds of the invention display at least 75%, preferably at least 90%, such as in excess of 95%, enantiomeric purity around the carbon shared by the hydroxyl group and the R1 methylene function depicted in formula I. It is currently preferred that the compounds exhibit a high degree of enantiomeric purity of the steroisomeres as shown in the partial structure:

Group X can be either R or S stereochemistry.
As defined above X is H, OH, C1-C3Alk or C0-C3alkanediyl-O—C1-C3alkyl. Convenient values for X include OH and C0-C3alkanediyl-O—C1-C3alkyl especially methoxy (i.e. C0) and hydroxymethyl. A currently favoured value for X is H or OH.
As recited above, L is OH, F, NH2, NHC1-C3Alk, N(C1-C3Alk)2, wherein the NHC1-C3Alk and N(C1-C3Alk)2 preferably are NHMe and NHMe2 respectively. A currently preferred value for L is fluoro and a more preferred value is OH.
The compounds of the invention can have 2 chain atoms between the carbonyl depicted in formula I and function E (i.e. n is 0). Other embodiments of the invention comprise 3 or 4 chain atoms between the carbonyl and function E, i.e. n is 1 or 2 respectively. In favoured embodiments of the invention the compounds have 3 chain atoms between the carbonyl and function E, i.e. n is 1.
Conveniently, the compounds of the invention comprise a hydrazide function, that is E is N, as it is believed that this configuration pitches the R2-methylene side chain at an advantageous angle relative to the S1′ (or S1) pocket of HIV protease, for example when A″ is according to formula V. However the optimal angle will, of course depend on other interactions along the backbone, side chains and termini of the compounds and thus additional embodiments of the invention comprise CH at function E.
As defined above, R1 is R1′, OR1′ or SR1′ wherein R1′ is C1-C6allyl, but is especially C0-C3alkanediylcarbocyclyl or C0-3alkanediylheterocyclyl. Typical examples of such species are recited below. Any of these species is optionally substituted with up to 3 substituents independently selected from R10 as defined above. Convenient optional substituents to R1′ include one or two substituents selected from halo, oxo, cyano, C1-C6Alk, C0-C3alkanediylcarbocyclyl, C0-C3alkanediylheterocyclyl, Y—NRaRb, Y—O—Rb; where Y is a bond or C1-C3Alk, Ra is H or C1-C3Alk and Rb is H or C1-C3Alk. Particularly preferred substituents include fluoro, C1-C3Alk, C0-C1alkanediylcarbocyclyl, C0-C1alkanediylheterocyclyl.
Conveniently, the C0-C3alkanediyl linker moiety of such C0-C3alkanediylcarbocyclyl or C0-3alkanediylheterocyclyl species as R1 or the optional substituent thereto defines methylene or even more preferably a bond, i.e. R1′ or the substituent is simply an optionally substituted carbocyclyl or heterocyclyl, such as optionally substituted phenyl or optionally substituted pyridyl, pyrazinyl, pyrimidinyl or pyridazinyl.
Preferably R1 is R1′ or OR1′.
In one embodiment of the present invention the R10 substituent of R1 is Y—O—Rb where Y is a bond and Rb is an optionally substituted C0-C3alkanediylaryl or C0-C3alkanediylheteroaryl. The optional substituent is preferably C1-C3Alk, such as methyl
Preferred structures for R1 according to this embodiment include:

According, other suitable values for R1 include phenyl, pyrid-2-yl, pyrid-3-yl, pyrid-4-yl, pyrimidin-2-yl, pyrimidinyl-4-, pyrazin-2-yl, pyrazin-3-ylyl or pyridazin-3-yl, pyridazin-4-yl or triazinyl; or mono- or di-halo substituted phenyl, such mono- or di-fluoro substituted phenyl.
As defined above, R2 is C1-C6Alk, but especially C0-C3alkanediylcarbocyclyl, C0-3alkanediylheterocyclyl, any of which species can be substituted with up to 3 substituents independently selected from R10. The optional substituent is preferably one or two members chosen from halo, oxo, cyano, C1-C6Alk, C0-C3alkanediylcarbocyclyl, C0-C3alkanediylheterocyclyl, Y—NRaRb, Y—O—Rb; where Y is a bond or C1-C3Alk, Ra is H or C1-C3Alk and Rb is H or C1-C3Alk. Currently favoured substituents include fluoro, C1-C3Alk, methylenecarbocyclyl or methyleneheterocyclyl, but especially a substituent such as optionally substituted carbocyclyl or heterocyclyl, for example in the para position of the R cyclic group.
Conveniently, the C0-C3alkanediyl linker moiety of such C0-C3alkanediylcarbocyclyl or C0-C3alkanediylheterocyclyl species as R2 or the optional substituent thereto defines methylene or even more preferably a bond, i.e. R2 or the substituent is simply an optionally substituted carbocyclyl or heterocyclyl, such as optionally substituted phenyl or optionally substituted pyridyl, pyrazinyl, pyrimidinyl or pyridazinyl
Accordingly suitable values for R2 include phenyl, pyrid-2-yl, pyrid-3-yl, pyrid-4-yl, pyrimidin-2-yl, pyrimidiny-4-yl, pyrazin-2-yl, pyrazin-3-ylyl or pyridazin-3-yl, pyridazin-4-yl or triazinyl; or phenyl substituted, especially in the para position with an aryl carbocyclic ring such as phenyl or heterocyclic ring, such as heteroarylic group as defined below, for example pyrid-2-yl, pyrid-3-yl or pyrid-4-yl.
Turning now to the terminal amide A′, one convenient embodiment comprises a bicyclic ring system comprising a first 5 or 6 membered saturated ring optionally containing an oxygen hetero atom, and optionally substituted with hydroxy or methyl, having fused thereto a second 5 or 6 membered unsaturated ring optionally containing one or two hetero atoms selected from S, O and N, and optionally mono- or di-fluoro substituted.
Conveniently in this embodiment the bond to the amide and rest of the molecule extends from carbon 1 of said saturated ring. Suitably the optional hydroxy substitutent in this embodiment is at carbon 2 of said saturated ring. Alternatively an oxygen hetero atom is provided, typically at position 3 of a 5 membered saturated ring or position 4 of a 6 membered saturated ring.
The second ring in this embodiment of A′ is conveniently 5-membered and comprises a sulphur hetero atom or an oxygen hetero atom. Alternatively, the said second ring is typically a fused pyridyl as described in WO9845330 or an optionally substituted phenyl, for example a fused phenyl wherein the substituent is mono- or di-fluoro.
Representative A′ groups in this embodiment of the invention include:

An alternative embodiment of the compounds of the invention includes those wherein A′ is a group of formula (II), thereby defining a compound of the formula:

A further alternative embodiment of the compounds of the invention includes those wherein A′ is a group of formula (II′), thereby defining a compound of the formula:

As recited above R3 is H; or R3 is C1-C6Alk, C0-C3alkanediylcarbocyclyl, C0-3alkanediylheterocyclyl, any of which is optionally substituted with up to three substituents independently selected from R11. Convenient values for R3 include optionally substituted C0-C3alkylheterocycylyl and especially H or optionally substituted C1-C6Alk. Favoured R3 values include C1-C6Alk such as isopropyl or t-butyl optionally substituted with hydroxy or methoxy or halo, such as fluoro.
Preferred values for R3 are isopropyl, t-butyl, 2-fluoro-1-methylethyl, 2-hydroxy-1-methylethyl, 2-methoxy-1-methylethyl, 2-fluoro-1,1-dimethylethyl, 2-hydroxy-1,1-dimethylethyl and 2-methoxy-1,1-dimethylethyl.
The optional substituent to R3 is as defined above. Representative values include oxo, cyano or especially halo or Y—O—Ra, where Y is a bond or C1-C3Alk and Ra is H or C1-C3Alk.
As recited above R4 in Formulae I, IIa and II′a is C1-C6Alk, C0-C3alkanediylcarbocyclyl or C0-C3alkanediylheterocyclyl, any of which is optionally substituted with up to three substituents independently selected from R10. Favoured values of R4 include optionally substituted C1-C6Alk, especially methyl or ethyl or optionally substituted methyl or ethyl.
Convenient optional substituents to R4 include halo, oxo, cyano, azido, nitro, C1-C6Alk, C0-C3alkanediylcarbocyclyl, C0-C3alkanediylheterocyclyl, Y—NRaRb or Y—O—Rb wherein;
Y is a bond or C1-C3Alk;
Ra is H or C1-C3Alk;
Rb is H or C1-C6Alk, C0-C3alkanediylcarbocyclyl or C0-C3alkanediylheterocyclyl.
Preferred values for R4 are fluoroethyl, difluoroethyl, trifluoroethyl and methoxyethyl.
Preferred optional substituents to R4 include halo, oxo, C1-C6Alk, C0-C3alkanediylcarbocyclyl, C0-C3alkanediylheterocyclyl or Y—O—Rb, especially halo or Y—O—Rb.
Formula II may comprise the S or R stereochemistry at the chiral centre to which R3 is attached, or a racemate thereof, but it is currently preferred that it has the stereochemistry shown in the partial structure:

Alternatively A′ may comprise the substructure:
where R3 is H; or R3 is C1-C6Alk, C0-C3alkanediylcarbocyclyl, C0-3alkanediylheterocyclyl, any of which is optionally substituted with up to three substituents independently selected from R11; R5 is C1-C6Alk, C0-C3alkanediylcarbocyclyl, C0-3alkanediylheterocyclyl, any of which is optionally substituted with up to three substituents independently selected from R10; and Z is bond, —NH—, —O—; Preferred values for R3 are as defined above in respect of formula II.
Formula III may comprise the S or R stereochemistry at the chiral centre to which R3 is attached, or a racemate thereof, but it is currently preferred that it has the stereochemistry shown in the partial structure:

Currently preferred values for Z is O. Favoured values of R5 include optionally substituted C1-C6Alk, especially methyl or optionally substituted methyl.
A favoured value for A′ is formula IV, thus defining a compound of the formula

Representative values for formula IV include monocyclic furans where Rx is H, C1-C3alkyloxy, C1-C3 straight or branched alkyl optionally substituted with halo, hydroxy, C1-C3alkyloxy. Representative values within this series include those wherein Rx is H, or wherein Rx is C1-C3Alk substituted at chain carbon 1 with halo, hydroxy or C1-C2Alk. Favoured values include those wherein Rx is hydroxymethyl, 1-hydroxyethyl, 1-hydroxypropyl, fluoromethyl, 1-fluoroethyl or 1-fluoropropyl and those wherein Rx is methoxymethyl, ethoxymethyl, 1-methoxyethyl, 1-ethoxyethyl, 1-methoxypropyl or 1-ethoxypropyl. Specially preferred compounds according to formula IVa are those wherein n is 1 and/or L is OH.
Alternatively Rx defines a further furanyl or pyranyl ring fused to the depicted furan and optionally substituted with halo or C1-C3Alk. Representative examples include those wherein the heterocyclic oxygen is located as follows:

Turning now to the order other terminal amide A″, as defined above, this is selected from formula V, VI, VII or VIII.
Representative values for formula VI, especially when A′ is of formula II, IV or a bicyclic ring system, include those of the formula:

Favoured compounds according to this embodiment include compounds according to formulae VIa and VIb:

Further favoured compounds according to this embodiment include compounds according to formulae VIc and VId:

Specially preferred compounds according to formula VIa, VIb, VIc and VId are those wherein n is 1, R1 is phenyl and/or L is OH.
Suitable building blocks for the preparation of compounds according to this embodiment of the invention are described herein and in WO99/48885 and WO94/05639.
Conveniently A″ is of formula V, thus defining a compound of the formula:

As recited above, R8 is H; or R8 is C1-C6Alk, C0-C3alkanediylcarbocyclyl, C0-3alkanediylheterocyclyl, any which is optionally substituted with up to three substituents independently selected from R11. Conveniently R8 is H, optionally substituted C1-C6Alk or optionally substituted C0-C3alkanediylcarbocyclyl. Currently favoured values for R8 include H or optionally substituted C1-C6Alk, especially i-propyl or t-butyl.
R8 is optionally substituted with 1 to 3 members independently selected from R11. Representative optional substituents include oxo, cyano, C1-C3Alk or especially halo or Y—O—Ra, where Y is a bond or C1-C3Alk and Ra is H or C1-C3Alk.
As recited above, R9 is C1-C6Alk, C0-C3alkanediylcarbocyclyl, C0-3alkanediylheterocyclyl, any of which is optionally substituted with up to three substituents independently selected from R10; and W is a bond, —NH— or —O—. Conveniently, R9 is optionally substituted C1-C6Alk or C0-C3alkanediylcarbocyclyl, especially optionally substituted methyl, or unsubstituted methyl.
Representative optional substituents to R9 include halo, oxo, cyano, azido, nitro, C1-C6Alk, C0-C3alkanediylcarbocyclyl, C0-C3alkanediylheterocyclyl, Y—NRaRb or Y—O—Rb where Y is a bond or C1-C3Alk, Ra is H or C1-C3Alk and Rb is H or C1-C6Alk, C0-C3alkanediylcarbocyclyl or C0-C3alkanediylheterocyclyl. Particularly preferred optional substituents, for example when R9 is methyl include halo, oxo, C1-C6Alk, C0-C3alkanediylcarbocyclyl, C0-C3alkanediylheterocyclyl or Y—O—Rb.
When A″ is of formula V, it is currently preferred that W is —O—.
Formula V may comprise the S or R stereochemistry at the chiral centre to which R8 is attached, or a racemate thereof, but it is currently preferred that it has the stereochemistry shown in the partial structure:

One embodiment when A″ is according to formula V includes compounds wherein R9 is an optionally substituted heterocyclyl either directly bonded to W, (i.e. C0) or bonded to W via an C1-C3alkanediyl chain for example a methylene chain (i.e. C1).
Preferred compounds according to this embodiment include those having the structure according to formulae Va and Vb:

Specially preferred compounds according to formulae Va and Vb are those wherein n is 1, R1 is phenyl and/or L is OH.
Suitable building blocks for the preparation of compounds according to this embodiment of the invention are described herein and in WO98/00410 and WO96/039398.
Another embodiment when A″ is according to formula V includes compounds wherein W is a bond and R9 is C0-C3alkanediylcarbocyclyl or C0-C3alkanediylheterocyclyl, the carbocyclyl and heterocyclyl being optionally substituted.
Preferred compounds according to this embodiment include those having the structure according to formulae Vc and Vd:

Specially preferred compounds according to formula Vc and Vd are those wherein n is 1, R1 phenyl and/or L is OH
Suitable building blocks for the preparation of compounds according to this embodiment of the invention are described herein and in U.S. Pat. No. 5,196,438.
When A″ is of formula VII, it is currently preferred that R8 is as described above and R9 is C1-C6Alk such as methyl.
Conveniently A″ is of formula VIII, thus defining compounds of formula VIIIa:

As recited above, R15 is carbocyclyl or heterocyclyl, any of which is optionally substituted with up to three substituents independently selected from C1-C3Alk, hydroxy, oxo, halo, Q is O, NR8 or a bond and r and q are independently 0 or 1.
Representative values for R15 are 5 to 6 membered, optionally substituted, aromatic rings containing 0 to 2 heteroatoms, the heteroatoms being independently selected from N, O and S.
Convenient optional substituents to R15 include C1-C3Alk, such as methyl, ethyl, propyl or isopropyl.
Representative compounds in this embodiment of the invention are those wherein Q is a bond and r and q are both zero.
Preferred compounds according to this embodiment are those with the structures according to formulae VIIIb and VIIIc:

Specially preferred compounds according to formula VIIIb and VIIIc are those wherein n is 1, R1 is phenyl and/or L is OH.
Suitable building blocks for the preparation of compounds according to this embodiment of the invention are described herein and in U.S. Pat. No. 5,484,926 and U.S. Pat. No. 5,952,343.
Further favoured compounds wherein A″ is according to formula VIII are those wherein Q is O.
Preferred compounds according to this embodiment include those having the structures according to formulae VIIId, VIIIe, VIIIf and VIIIg:

Specially preferred compounds according to formula VIIId, VIIIe, VIIIf and VIIIg are those wherein n is 1, R1 is phenyl and/or L is OH.
Suitable building blocks for the preparation of compounds according to this embodiment of the invention are described herein and in WO98/00410 and WO96/39398.
Further favoured compounds wherein A″ is according to formula VIII are those wherein Q is CR8.
Preferred compounds according to this embodiment include those having the structure according to formulae VIIIh and VIIIi:

Specially preferred compounds according to formula VIIIh and VIIIi are those wherein n is 1, R1 is phenyl and/or L is OH.
Suitable building blocks for the preparation of compounds according to this embodiment of the invention are described herein and in U.S. Pat. No. 6,372,905 and WO97/21685.
Convenient intermediates specially useful for the synthesis of compounds of formula (I) wherein n is 0, include epoxides having the general structure depicted below:
wherein A′ and R1 are as defined above.
Further intermediates, specially useful for the synthesis of compounds of formula (I) wherein n is 1, include epoxides and alcohols having the structures shown below:
wherein R1 is as defined above.
‘C0-C3alkanediyl-O—C1-C3alkyl’ as applied herein is meant to include C1-C3alkoxy groups such as methoxy, ethoxy, n-propoxy, isopropoxy directly bonded (i.e. C0) or through an intermediate methylene, ethanediyl, 1,3-propanediyl or 1,3-propanediyl chain.
‘C1-C6Alk’ as applied herein is meant to include straight and branched aliphatic carbon chain substituents containing from 1 to 6 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, pentyl, isopentyl and hexyl and any simple isomers thereof. The Alk group may have an unsaturated bond. Additionally, any C atom in C1-C6Alk may optionally be substituted by one, two or where valence permits three halogens and/or a heteroatom S, O, NH. If the heteroatom is located at a chain terminus then it is appropriately substituted with one or 2 hydrogen atoms, such as OH or NH2. Preferably the C1-C6Alk is small, saturated and unsubstituted or substituted with halo such as fluoro. C1-C4Alk and C1-C5Alk have the corresponding meaning to C1-C6Alk adjusted as necessary for the carbon number. Me denotes a methyl group.
‘C1-C3Alk’ as applied herein is meant to include methyl, ethyl, propyl, isopropyl, cyclopropyl, any of which may be optionally substituted as described in the paragraph above or in the case of C2 or C3, bear an unsaturated bond such as CH═CH2.
‘C0-C3alkanediyl’ as applied herein is meant to include bivalent straight and branched aliphatic carbon chains such as methylene, ethanediyl, 1,3-propanediyl, 1,2-propanediyl.
‘Amino’ includes NH2, NHC1-C3Alk or N(C1-C3Alk)2.
‘Halo’ or halogen as applied herein is meant to include F, Cl, Br, I, particularly chloro and preferably fluoro.
‘C0-C3alkanediylaryl’ as applied herein is meant to include a phenyl, naphthyl or phenyl fused to C3-C7cyclopropyl such as indanyl, which aryl is directly bonded (i.e. C0) or through an intermediate methylene, ethanediylyl, 1,2-propanediyl, or 1,3-propanediyl group as defined for C0-C3alkanediyl above. Unless otherwise indicated the aryl and/or its fused cycloalkyl moiety is optionally substituted with 1-3 substituents selected from halo, hydroxy, nitro, cyano, carboxy, C1-C6Alk, C1-C6alkoxy, C1-C6alkoxy-C1-C6Alk, C1-C6alkanoyl, amino, azido, oxo, mercapto, nitro C0-C3alkanediylcarbocyclyl, C0-C3alkanediylheterocyclyl. “Aryl” has the corresponding meaning.
‘C0-C3alkanediylcarbocyclyl’ as applied herein is meant to include C0-C3alkanediylaryl and C0-C3alkanediylC3-C7cycloalkyl. Unless otherwise indicated the aryl or cycloalkyl group is optionally substituted with 1-3 substituents selected from halo, hydroxy, nitro, cyano, carboxy, C1-C6Alk, C1-C6alkoxy, C1-C6alkoxyC1-C6Alk, C1-C6alkanoyl, amino, azido, oxo, mercapto, nitro, C0-C3alkanediylcarbocyclyl and/or C0-C3alkanediylheterocyclyl. “Carbocyclyl” has the corresponding meaning, i.e. where the C0-C3alkanediyl linkage is absent
‘C0-C3alkanediylheterocycylyl’ as applied herein is meant to include a monocyclic, saturated or unsaturated, heteroatom-containing ring such as piperidinyl, morpholinyl, piperazinyl, pyrazolyl, imidazolyl, oxazolyl, isoxazolyl, thiazinolyl, isothiazinolyl, thiazolyl, oxadiazolyl, 1,2,3-triazolyl, 1,2,4-triazolyl, tetrazolyl, furanyl, thienyl, pyridyl, pyrimidinyl, pyridazinyl, pyrazinyl, pyrazolyl, or any of such groups fused to a phenyl ring, such as quinolinyl, benzimidazolyl, benzoxazolyl, benzisoxazolyl, benzothiazinolyl, benzisothiazinolyl, benzothiazolyl, benzoxadiazolyl, benzo-1,2,3-triazolyl, benzo-1,2,4-triazolyl, benzotetrazolyl, benzofuranyl, benzothienyl, benzopyridyl, benzopyrimidinyl, benzopyridazinyl, benzopyrazinyl, benzopyrazolyl etc, which ring is bonded directly i.e. (C0), or through an intermediate methyl, ethyl, propyl, or isopropyl group as defined for C0-C3alkanediyl above. Any such non-saturated rings having an aromatic character may be referred to as heteroaryl herein. Unless otherwise indicated the hetero ring and/or its fused phenyl moiety is optionally substituted with 1-3 substituents selected from halo, hydroxy, nitro, cyano, carboxy, C1-C6Alk, C1-C6alkoxy, C1-C6alkoxyC1-C6Alk, C1-C6alkanoyl, amino, azido, oxo, mercapto, nitro, C0-C3-carbocyclyl, C0-C3heterocyclyl. “Heterocyclyl” and “Heteroaryl” has the corresponding meaning, i.e. where the C0-C3alkanediyl linkage is absent.
Typically the terms ‘optionally substituted C0-C3alkanediylcarbocyclyl’ and ‘optionally substituted C0-C3alkanediylheterocyclyl’ refers preferably to substitution of the carbocyclic or heterocyclic ring.
Typically heterocyclyl and carbocyclyl groups are thus a monocyclic ring with 5 or especially 6 ring atoms, or a bicyclic ring structure comprising a 6 membered ring fused to a 4, 5 or 6 membered ring.
Typical such groups include C3-C8cycloalkyl, phenyl, benzyl, tetrahydronaphthyl, indenyl, indanyl, heterocyclyl such as from azepanyl, azocanyl, pyrrolidinyl, piperidinyl, morpholinyl, thiomorpholinyl, piperazinyl, indolinyl, pyranyl, tetrahydropyranyl, tetrahydrothiopyranyl, thiopyranyl, furanyl, tetrahydrofuranyl, thienyl, pyrrolyl, oxazolyl, isoxazolyl, thiazolyl, imidazolyl, pyridyl, pyrimidinyl, pyrazinyl, pyridazinyl, tetrazolyl, pyrazolyl, indolyl, benzofuranyl, benzothienyl, benzimidazolyl, benzthiazolyl, benzoxazolyl, benzisoxazolyl, quinolinyl, tetrahydroquinolinyl, isoquinolinyl, tetrahydroisoquinolinyl, quinazolinyl, tetrahydroquinazolinyl and quinoxalinyl, any of which may be optionally substituted as defined herein.
The saturated heterocycle thus includes radicals such as pyrrolinyl, pyrrolidinyl, pyrazolinyl, pyrazolidinyl, piperidinyl, morpholinyl, thiomorpholinyl, pyranyl, thiopyranyl, piperazinyl, indolinyl, azetidinyl, tetrahydropyranyl, tetrahydrothiopyranyl, tetrahydrofuranyl, hexahydropyrimidinyl, hexahydropyridazinyl, 1,4,5,6-tetrahydropyrimidinylamine, dihydro-oxazolyl, 1,2-thiazinanyl-1,1-dioxide, 1,2,6-thiadiazinanyl-1,1-dioxide, isothiazolidinyl-1,1-dioxide and imidazolidinyl-2,4-dione, whereas the unsaturated heterocycle include radicals with an aromatic character such as furanyl, thienyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, pyrazolyl, isoxazolyl, isothiazolyl, oxadiazolyl, triazolyl, tetrazolyl, thiadiazolyl, pyridinyl, pyridazinyl, pyrimidinyl, pyrazinyl, indolizinyl, indolyl, isoindolyl. In each case the heterocycle may be condensed with a phenyl ring to form a bicyclic ring system.
The compounds of the invention can form salts which form an additional aspect of the invention. Appropriate pharmaceutically acceptable salts of the compounds of Formula I include salts of organic acids, especially carboxylic acids, including but not limited to acetate, trifluoroacetate, lactate, gluconate, citrate, tartrate, maleate, malate, pantothenate, isethionate, adipate, alginate, aspartate, benzoate, butyrate, digluconate, cyclopentanate, glucoheptanate, glycerophosphate, oxalate, heptanoate, hexanoate, fumarate, nicotinate, palmoate, pectinate, 3-phenylpropionate, picrate, pivalate, proprionate, tartrate, lactobionate, pivolate, camphorate, undecanoate and succinate, organic sulphonic acids such as methanesulphonate, ethanesulphonate, 2-hydroxyethane sulphonate, camphorsulphonate, 2-napthalenesulphonate, benzenesulphonate, p-chlorobenzenesulphonate and p-toluenesulphonate; and inorganic acids such as hydrochloride, hydrobromide, hydroiodide, sulphate, bisulphate, hemisulphate, thiocyanate, persulphate, phosphoric and sulphonic acids. The compounds of Formula I may in some cases be isolated as the hydrate.
It will be appreciated that the invention extends to prodrugs, solvates, complexes and other forms releasing a compound of formula I in vivo.
While it is possible for the active agent to be administered alone, it is preferable to present it as part of a pharmaceutical formulation. Such a formulation will comprise the above defined active agent together with one or more acceptable carriers/excipients and optionally other therapeutic ingredients. The carrier(s) must be acceptable in the sense of being compatible with the other ingredients of the formulation and not deleterious to the recipient.
The formulations include those suitable for rectal, nasal, topical (including buccal and sublingual), vaginal or parenteral (including subcutaneous, intramuscular, intravenous and intradermal) administration, but preferably the formulation is an orally administered formulation. The formulations may conveniently be presented in unit dosage form, e.g. tablets and sustained release capsules, and may be prepared by any methods well known in the art of pharmacy.
Such methods include the step of bringing into association the above defined active agent with the carrier. In general, the formulations are prepared by uniformly and intimately bringing into association the active agent with liquid carriers or finely divided solid carriers or both, and then if necessary shaping the product. The invention extends to methods for preparing a pharmaceutical composition comprising bringing a compound of Formula I or its pharmaceutically acceptable salt in conjunction or association with a pharmaceutically acceptable carrier or vehicle. If the manufacture of pharmaceutical formulations involves intimate mixing of pharmaceutical excipients and the active ingredient in salt form, then it is often preferred to use excipients which are non-basic in nature, i.e. either acidic or neutral.
Formulations for oral administration in the present invention may be presented as discrete units such as capsules, cachets or tablets each containing a predetermined amount of the active agent; as a powder or granules; as a solution or a suspension of the active agent in an aqueous liquid or a non-aqueous liquid; or as an oil-in-water liquid emulsion or a water in oil liquid emulsion and as a bolus etc.
With regard to compositions for oral administration (e.g. tablets and capsules), the term suitable carrier includes vehicles such as common excipients e.g. binding agents, for example syrup, acacia, gelatin, sorbitol, tragacanth, polyvinylpyrrolidone (Povidone), methylcellulose, ethylcellulose, sodium carboxymethylcellulose, hydroxypropylmethylcellulose, sucrose and starch; fillers and carriers, for example corn starch, gelatin, lactose, sucrose, microcrystalline cellulose, kaolin, mannitol, dicalcium phosphate, sodium chloride and alginic acid; and lubricants such as magnesium stearate, sodium stearate and other metallic stearates, glycerol stearate stearic acid, silicone fluid, talc waxes, oils and colloidal silica. Flavouring agents such as peppermint, oil of wintergreen, cherry flavouring or the like can also be used. It may be desirable to add a colouring agent to make the dosage form readily identifiable. Tablets may also be coated by methods well known in the art.
A tablet may be made by compression or moulding, optionally with one or more accessory ingredients. Compressed tablets may be prepared by compressing in a suitable machine the active agent in a free flowing form such as a powder or granules, optionally mixed with a binder, lubricant, inert diluent, preservative, surface-active or dispersing agent. Moulded tablets may be made by moulding in a suitable machine a mixture of the powdered compound moistened with an inert liquid diluent. The tablets may be optionally be coated or scored and may be formulated so as to provide slow or controlled release of the active agent.
Other formulations suitable for oral administration include lozenges comprising the active agent in a flavoured base, usually sucrose and acacia or tragacanth; pastilles comprising the active agent in an inert base such as gelatin and glycerin, or sucrose and acacia; and mouthwashes comprising the active agent in a suitable liquid carrier.
The appropriate dosage will depend upon the indications and the patient, and is readily determined by conventional animal drug metabolism and pharmacokinetics (DMPK) or clinical trials and in silico prediction software.
In treating HIV, the compounds of formula I are typically administered in an amount to achieve a plasma level of around 100 to 5000 nM, such as 300 to 2000 nM. This corresponds to a dosage rate, depending on the bioavailability of the formulation, of the order 0.01 to 10 mg/kg/day, preferably 0.1 to 2 mg/kg/day. A typical dosage rate for a normal adult will be around 0.05 to 5 g per day, preferably 0.1 to 2 g such as 500-750 mg, in one to four dosage units per day. As with all pharmaceuticals, dosage rates will vary with the size and metabolic condition of the patient as well as the severity of the infection and may need to be adjusted for concomitant medications.
In general dosages of from about 3 mg to approximately 1.6 grams per person per day, divided into 1 to 3 single doses, are suitable. A typical dosage for adult patients is 50-800, more preferably 400-600 twice, or most preferably once daily. As elaborated below HIV inhibitors are typically co-administered in a unit dosage form with other HIV inhibitors or metabolism modifying agents and the dosage regime (QQ, BiD TiD, fast/with food etc) for such co-administered drugs will of course necessitate concomitant adjustment of the dosage regime for formula I
As is good prescribing practice with antiviral therapy, the compounds of formula I are typically co-administered with other HCV therapies to avoid the generation of drug escape mutants. However, certain antifectives can induce a synergistic response, allowing one or both of the active ingredients to be administered at a lower dose that the corresponding monotherapy. For example in drugs prone to rapid metabolism by Cyp3A4, co-dosing with the HIV protease inhibitor ritonavir can allow lower dosage regimes to be administered. The compound of the invention and the or each further antiviral agent are typically co-administered at molar ratios reflecting their respective activities and bioavailabilities. Generally such ratio will be of the order of 25:1 to 1:25, relative to the compound of formula I, but may be lower, for instance in the case of cytochrome antagonists such as ritonavir.
Representative HIV antivirals include NRTI such as alovudine (FLT), zudovudine (AZT, ZDV), stavudine (d4T, Zerit), zalcitabine (ddC), didanosine (ddI, Videx), abacavir, (ABC, Ziagen), lamivudine (3TC, Epivir), emtricitabine (FTC, Emtriva), racevir (racemic FTC), adefovir (ADV), entacavir (BMS 200475), alovudine (FLT), tenofovir disoproxil fumarate (TNF, Viread), amdoxavir (DAPD), D-d4FC (DPC-817), -dOTC (Shire SPD754), elvucitabine (Achillion ACH-126443), BCH 10681 (Shire), SPD-756, racivir, MIV-606 (Medivir), D-FDOC, GS7340, INK-20 (thioether phospholipid AZT, Kucera), 2′3′-dideoxy-3′-fluoroguanosine (FLG) & its prodrugs such as MIV-210, reverset (RVT, D-D4FC, Pharmasset DPC-817).
Representative NNRTI include delavirdine (Rescriptor), efavirenz (DMP-266, Sustiva), nevirapine (BIRG-587, Viramune), (+)calanolide A and B (Advanced Life Sciences), capravirine (AG1549f S-1153; Pfizer), GW-695634 (GW-8248; GSK), MIV-150 (Medivir), MV026048 (R-1495; Medivir AB/Roche), NV-05 2 2 (Idenix Pharm.), R-278474 (Johnson & Johnson), RS-1588 (Idenix Pharm.), TMC-120/125 (Johnson & Johnson), TMC-125 (R-165335; Johnson & Johnson), UC-781 (Biosyn Inc.) and YM215389 (Yamanoushi).
Representative HIV protease inhibitors include PA-457 (Panacos), KPC-2 (Kucera Pharm.), 5 HGTV-43 (Enzo Biochem), amprenavir (VX-478, Agenerase), atazanavir (Reyataz), indinavir sulfate (MK-639, Crixivan), Lexiva (fosamprenavir calcium, GW-433908 or 908, VX-175), ritonavir (Norvir), lopinavir+ritonavir (ABT-378, Kaletra), tipranavir, nelfinavir mesylate (Viracept), saquinavir (Invirase, Fortovase), AG1776 (JE-2147, KNI-764; Nippon Mining Holdings), AG-1859 (Pfizer), DPC-681/684 (BMS), GS224338 (Gilead Sciences), KNI-272 (Nippon Mining Holdings), Nar-DG-35 (Narhex), P(PL)-100 (P-1946; Procyon Biopharma), P-1946 (Procyon Biopharma), R-944 (Hoffmann-LaRoche), RO-0334649 (Hoffmann-LaRoche), TMC-114 (Johnson & Johnson), VX-385 (GW640385; GSK/Vertex), VX-478 (Vertex/GSK).
Other HIV antivirals include entry inhibitors, including fusion inhibitors, inhibitors of the CD4 receptor, inhibitors of the CCR5 co-receptor and inhibitors of the CXCR4 coreceptor, or a pharmaceutically acceptable salt or prodrug thereof. Examples of entry inhibitors are AMD-070 (AMD 11070; AnorMed), BlockAide/CR (ADVENTRX Pharm.), BMS 806 (BMS-378806; BMS), Enfurvirtide (T-20, R698, Fuzeon), KRH1636 (Kureha Pharmaceuticals), ONO-4128 (GW-873140, AK-602, E-913; ONO Pharmaceuticals), PRO-140 (Progenics Pharm), PRO-542 (Progenics Pharm.), SCH-D (SCH-417690; Schering-Plough), T-1249 (R724; Roche/Trimeris), TAK-220 (Takeda Chem. Ind.), TNX-355 (Tanox) and UK-427,857 (Pfizer). Examples of integrase inhibitors are L-870810 (Merck & Co.), c-2507 (Merck & Co.) and S(RSC)-1838 (shionogi/GSK).
Many HIV patients are co-infected, or prone to superinfection, with other infectious diseases. Accordingly, a further aspect of the invention provides combination therapies comprising the compound of the invention co-formulated in the same dosage unit or co-packaged with at least one further anti-infective pharmaceutical. The compound of the invention and the at least one further antinfective are administered simultaneously or sequentially, typically at doses corresponding to the monotherapy dose for the agent concerned.
Typical coinfections or superinfections include hepatitis B virus (HBV) or Hepatitis C virus (HCV). Accordingly the compound of the invention is advantageously co-administered (either in the same dosage unit, co-packaged or separately prescribed dosage unit) with at least one HCV antiviral and/or at least one HBV antiviral.
Accordingly the compound of the invention is advantageously co-administered (either in the same dosage unit, co-packaged or separately prescribed dosage unit) with at least one HCV antiviral and/or at least one HBV antiviral.
Examples of HBV antivirals include lamivudine and 2′3′-dideoxy-3′-fluoroguanosine (FLG) & its prodrugs such as the 5′-O-lacytlvalyl prodrug MIV-210. These HBV antivirals are particularly convenient as they are simultaneously active against both HBV and HIV.
Examples of HCV antiviral for co-administration with formula I include immune modifiers such as ribavirin or interferons, nucleoside HCV polymerase inhibitors or HCV protease inhibitors, many of which are currently under development.
The compounds of the invention are believed to counteract elevated LDL-cholesterol and/or triglyceride levels often appearing as a side effect of prior art HIV protease inhibitors. Accordingly the compounds of the invention are useful for replacing such prior art inhibitors in the ongoing dosage regimes of patients. Typically such patient has been or is undergoing antiretroviral therapy with one or more conventional HIV protease inhibitors and exhibits elevated plasma LDL-cholesterol and/or triglyceride levels. Such other HIV protease inhibitor(s) may be given as monotherapy or as part of an antiretroviral therapy which also includes one or more other antiretroviral drugs such as reverse transcriptase inhibitors or nonnucleoside reverse transcriptase inhibitors. Such candidates, although they may exhibit satisfactory viral suppression, may be of increased risk for hyperlipidemia and premature cardiovascular events.
The term “elevated plasma LDL-cholesterol and triglyceride levels” as used herein is based on the National Cholesterol Education Program (NCEP) clinical practice guidelines for the prevention and management of high cholesterol in adults.
In the latest guidelines issued in 2001, plasma levels of >130 mg/dL of LDLcholesterol and >150 mg/dL of triglycerides are considered elevated or “high”. The process of the present invention is particularly useful for those patients having plasma triglyceride levels of >200 mg/dL and for those patients with no risk factors or previous cardiovascular events having LDL-cholesterol levels of >160 mg/dL.
The definition of “elevated” LDL-cholesterol and triglyceride levels may, of course, change in the future as the NCEP continues to evaluate heart attack risk factors. It is intended, then, that the term “elevated LDL-cholesterol and triglyceride levels” as used will be consistent with current NCEP guidelines.
In one of its aspects, the present invention involves discontinuing the offending (the drug responsible for the elevated plasma LDL-cholesterol and/or triglyceride levels) HIV protease inhibitor from the above regimen and substituting therefore an amount of the compound of formula I which is effective to inhibit HIV and to reduce plasma LDL-cholesterol and/or triglyceride levels.
The dose of the compound of the invention to be employed depends on such factors as the body weight, age and individual condition of the patient to be treated and the mode of administration.
It is believed that the compounds according to some embodiments of the invention can in certain formulations interact favourably with cytochrome P450 monooxygenase and can improve the pharmacokinetics of drugs metabolized by this enzyme, including particularly other HIV protease inhibitors such as saquinavir, indinavir, nelfinavir, araprenavir, tipanavir and lopinavir. Thus, it may act in a similar way to ritonavir described in U.S. Pat. No. 6,037,157 to increase blood levels of the coadministered HIV protease inhibitor. Conveniently and in contradistinction to ritonavir it is believed that the compound of the invention may be employed in combination therapy with other HIV protease inhibitors at its normal therapeutic dose level instead of the sub-therapeutic dose levels used with ritonavir. Any such potentiating effect on other HIV protease inhibitors which are metabolized by cytochrome P450 monooxygenase, may allow the use of the compounds of the invention concomitantly with such other HIV protease inhibitors thereby allowing reduced dosages of such other HIV protease inhibitors to be used while maintaining the same degree of viral suppression. Conceivably the compound of the invention can be used in combination with other HIV protease inhibitors to reduce LDL-cholesterol and triglyceride levels in AIDS patients undergoing protease inhibitor therapy while still maintaining the desired level of viral suppression.
The appropriate dose of the HIV protease inhibitor being combined with the compounds of the invention can be determined by the following method which was used for the atazanavir/saquinavir combination, as disclosed in WO03020206. Atazanavir is a moderate inhibitor of the cytochrome P450 3A enzyme comparable to nelfinavir and indinavir, with a Ki of 2.4 μM. The latter two compounds increase the exposure of saquinavir (dosed at 1200 mg thrice-daily (TID) by 392 and 364%, respectively, at steady-state. A multiple-dose pharmacology study was completed to evaluate if a similar increase could be expected for the combination of atazanavir and saquinavir. This study showed a greater than 3-fold increase in exposure, due to combination with atazanavir, supporting a 1200 mg once-daily saquinavir dosing, was equivalent to the currently marketed saquinavir regimen of 1200 mg TID. Using a constant dose of atazanavir the range of saquinavir doses were studied to target the saquinavir exposure (AUC (area under the curve) and CMIN (minimum concentration)) similar to those in the literature. Similarly, appropriate dosing of other HIV protease inhibitors to be used in combination with the compound of the invention can be calculated.
Compounds of the invention are typically synthesized outlined below.
A method to prepare compounds according to the present invention wherein E is N and n is 0 is by reacting a suitable epoxide with a desired hydrazide derivative as illustrated in scheme 1.

A suitable derivative of malonic acid (1a) where R1 is as described above, can be transformed into an acrylic acid derivative (1b) by way of a Mannich reaction followed by in situ decarboxylation. Various derivatives of malonic acid are available commercially or they are easily prepared by the skilled person according to literature procedures. The acrylic acid can then be coupled to a desired amine A′-NH2, where A′ is as defined above, using standard peptide coupling conditions for example by using 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDAC), N-methylmorpholine (NMM) and 1-hydroxybenzotriazole (HOBT) or any other suitable conditions that are known by the skilled person, to give the acrylamide derivative (1c). Epoxidation of the double bond by any suitable method like using a peroxide for instance 3-chloroperoxybenzoic acid (mCPBA) provides the corresponding epoxide (1d). Subsequent opening of the formed epoxide by a suitable hydrazide (1e) optionally in the presence of titanium(IV) isopropoxide as described in JOC, 50, 1985 p. 1557 yields the tertiary alcohol (1f). If desired, the afforded hydroxy group can then be converted to a fluoride or a primary or secondary amine thus providing compounds according to general formula I wherein n is 0, X is H, E is N and L is F, NHC1-C3alkyl or N(C1-C3alkyl)2, as shown in scheme 2 below.

Reaction of the alcohol (1f) with a suitable fluorinating agent such as DAST or Deoxofluor or the like in a solvent like dichloromethane as described e.g. by Singh, R. P. and Shreve, J. M. in Synthesis, 17, 1999, p. 2561-2578, yields the corresponding fluoro compound (2a). Alternatively, the hydroxy group of the alcohol (1f) can be transferred to an amine using any convenient method described in the literature. For example the Mitsunobu procedure can be used, i.e. reaction of the alcohol (1f) with an azodicarboxylate such as DIAD or the like in the presence of triphenylphosphine followed by displacement with a desired amine to provide the corresponding amino derivative (2b). An alternative route to the amine (2b) is by transformation of the hydroxy group into a leaving group such as a derivative of sulphonic acid like a mesylate, triflate, tosylate or the like by treatment with the appropriate sulphonylating agent in a solvent like for instance pyridine or dichloromethane optionally in the presence of triethylamine or the like, followed by displacement of the leaving group with a desired primary or secondary amine NH2C1-C3alkyl or NH(C1-C3alkyl)2. Alternatively, the leaving group can be displaced with azide, or the hydroxy group can be converted directly to an azide by use of an azide transfer agent like diphenyl phosphoryl azide (DPPA), subsequent reduction of the introduced azide to an amine, by for example triphenylphosphine optionally in the presence of a base like triethylamine provides compounds wherein L is NH2 whereas a reductive amination of the afforded amine with a desired aldehyde or ketone provides secondary or tertiary amines.
The above described intermediates, for example the epoxide 1d, wherein A′ and R1 are as defined above are novel compounds and constitute a further aspect of the invention.
Various amines, A′-NH2, used in scheme 1 are available commercially or alternatively they can be prepared according to literature procedures. For example, amines wherein A′ is according to formula (IV) can be prepared as described by B. Samuelsson et al. in Bioorg. Med. Chem., 11, 2003, p. 1107-1115. Alternatively, they can be prepared from the corresponding alcohols A′-OH by transforming the hydroxy group to an amino group. This transformation can be effected by any suitable method known by the skilled person, for instance by converting the hydroxy group to a leaving group such as a halide like a bromide, chloride or iodide or to a derivative of sulphonic acid such as a mesylate, triflate or tosylate, followed by a nucleophilic displacement reaction with azide and finally reduction of the azide to the amine using any suitable reduction method such as catalytic hydrogenation. Suitable alcohols are described for example by A. K. Gosh et al. in J. Med. Chem., 1996, 39, 3278-3290.
A further alternative to prepare amines, A′-NH2, wherein A′ is according to formula (IV) is illustrated in scheme 3.

Addition of a bromide and a propargyloxy group to the double bond of the unsaturated ring (3a) effected for instance by reaction with N-bromosuccinimide and propargyl alcohol followed by a reductive ring closure reaction promoted by tri-n-butyltin hydride in the presence of a radical initiator for example 1,1′-azobis(isobutyronitrile) or the like yields bicyclic olefin (3c). The exocyclic double bond can then be cleaved oxidatively by subjecting the olefinic compound to the appropriate oxidation conditions such as treatment with osmium tertoxide in combination with sodium periodate which gives the keto derivative (3d). Reaction of the formed keto group with O-benzylhydroxylamine followed by reduction with a reducing agent like lithium aluminium hydride gives the corresponding amine (3f) as a racemic mixture. The racemic mixture can thereafter be separated according to procedures known in the art. For example, a diastereomeric mixture which can be separated by chromatographic methods, can be prepared by coupling of a chiral auxiliary compound such as a chiral amino acid for example Boc-L-phenylalanine, using standard peptide coupling methods. Separation of the mixture and thereafter cleavage of the auxiliary amino acid then provides the pure diastereomers of the desired amine (3f).
An example of the preparation of amine derivatives A′-NH2 used i.a. in scheme 1 wherein A′ is according to formula (II) is shown in scheme 4 below.

Coupling of a suitably N-protected, for example Boc protected, amino acid (4a), carrying the desired side chain R3 to an amino derivative (4b), where R3 and R4 are as defined above, using standard peptide coupling conditions, like using coupling reagents such as EDAC, NMM and HOBT in an inert solvent like dimethylformamide gives the amide (2Bc). Removal of the N-protecting group, by acidic treatment in the case of a Boc protecting group, for example by using trifluoroacetic acid in dichloromethane, gives the amine (4d). Amino acids (4a) used in the above scheme are commercially available or they can be prepared according to literature procedures. A method to prepare amino acids carrying a branched side chain is exemplified in Scheme 4A.

Treatment of the amino acid (4Aa), achieved as described by Rapoport et al. in J. Org. Chem., 55, (1990) p. 5017-5025, with one or two successive additions of a base such as potassium bis-(trimethylsilyl) amide (KHMDS) and methyl iodide provides mono or dimethylated amino acid (4Ab) respectively. Reduction of the side chain ester using a reagent like DIBAL followed by interchanging of the PhFl group for a Boc group effected by catalytic hydrogenation in the presence of Boc2O and a catalyst like Pd/C, provides the alcohol (4Ac). If desired, the hydroxy group of the afforded alcohol can subsequently be methylated for instance by treatment with a suitable methylating agent such as methyl iodide and a base like NaH which gives the methoxy compound (4Ae). Alternatively, the alcohol can be converted to the corresponding fluorocompound (4Ad) by treatment with a fluorinating agent such as DAST or the like, or any other suitable fluorinating method described herein or elsewhere can be used.
Amines, A′-NH2, wherein A′ is according to formula (III) can be prepared as exemplified in scheme 5.

Reaction of a natural or non-natural amino acid (5a) carrying the appropriate side chain R3 defined as above, with a desired acylating agent; a chloroformate (i) for the formation of compounds wherein W is O, an acid chloride (ii) for the formation of compounds wherein W is a bond or an isocyanate (iii) for the formation of compounds wherein W is NH, provides the acid (5b). The amine A′-NH2 (5d) can then be achieved by transforming the acid (5b) to the corresponding primary amide (5c) for example by treatment with an ammonia solution in the presence of isobutyl chloroformate and N-methylmorpholine in a solvent like dimethoxy ethane, followed by a rearrangement reaction brought about by treatment with [bis(trifluoroacetoxy)iodo]benzene optionally in the presence of pyridine as described e.g. by J-A. Fehreentz in J. Med. Chem., 2003, 46, 1191-1203.
Hydrazide derivatives (1e) used in scheme 1 can be prepared by reaction of an acid A″COOH or a derivative thereof, for instance an acid chloride or an acid anhydride, with a hydrazine R2CH2NHNH2 under standard peptide coupling conditions. Scheme 6 shows an example wherein A″ in the acid, A″COOH is according to formula (V) as defined above.

Reaction of a natural or non-natural amino acid (6a) carrying the appropriate side chain R8 defined as above, with a desired acylating agent as described in scheme 3 provides the acid (6b). The hydrazide derivative (6d) can then be achieved by coupling of a hydrazine derivative (6c) which is available either commercially or in the literature, using standard peptide coupling conditions as described above.
Compounds wherein A″ is according to formula (VII) can conveniently be prepared according to the above described route but with the use of a suitable sulphonylating agent like alkylsulphonyl chloride, R9—S(═O)2Cl, in the presence of a base like sodium hydroxide, instead of any of the depicted acylating agents i, ii or iii, in the reaction with amino acid 3a.
Hydrazides (1e) wherein A″ is according to formula (VI) can be prepared by reaction of an appropriate electrophilic carbonyl compound such as a chloroformate or an activated carbonate with the hydrazine derivative R2CH2NHNH2 as illustrated in scheme 7.

The alcohol (7a) can be converted to the corresponding activated carbonate (7b) or chloroformate by reaction of the hydroxy group with a suitable acylating agent like a carbonate such as dipyridyl carbonate or para-nitrophenyl chloroformate optionally in the presence of a base such as triethylamine or imidazole, or to a chloroformate by reaction with phosgene optionally in the presence of base like sodium hydrogen carbonate. The afforded electrophilic compound can then be reacted with a desired hydrazine derivative (7c) to give the corresponding hydrazide (7d). Alcohol (7a) is either commercially available or can be prepared for example as described by A. K. Ghosh et al. in J. Med. Chem., 1996, 39, 3278-3290.
The procedure described in scheme 7 can also be applied to other alcohols for instance optionally substituted carbocyclylmethanol, optionally substituted heterocyclylmethanol, optionally substituted carbocycloalcohol or optionally substituted heterocyclalcohol thus providing hydrazides wherein A″ is according to formula (VIII) as defined above.
A route to compounds according to general formula I wherein E is N and n is 1 is depicted in scheme 8.

Condensation of γ-butyrolactone (8a) with a suitable aldehyde (8b) in the presence of a base like potassium t-butoxide in an inert solvent like benzene, dichloromethane or the like provides the olefinic compound (8c). Epoxidation of the double bond can then be effected for example by using mCPBA in the presence of a catalytic amount of a radical initiator such as AIBN or the like which gives the epoxide (8d). Reductive opening of the epoxide by for instance catalytic hydrogenation in the presence of a catalyst like Pt(IV)O or the like, followed by ring opening of the lactone with a desired amine, A′-NH2, gives the diol (8f). Oxidation of the primary alcohol by any suitable oxidation method like for example using Dess-Martin periodinate provides the aldehyde (8 g) which subsequently can be reacted with a suitable hydrazide derivative (8 h) in a reductive amination reaction, using a reduction agent like NaCNBH4, to give the hydrazide (8i). The N-substituent CH2—R2 can then be introduced by alkylation of the β-nitrogen of the hydrazide with a desired alkylating agent (8j) wherein R2 is as defined above and X is a leaving group such as a halide like chloride, bromide or iodide or a derivative of sulphonic acid such as a triflate, mesylate or tosylate, thus providing the N-alkylated compound (8k). The above synthetic route can also be carried out starting from β-propiolactone thus giving compounds of general formula I wherein n is 0. The N-alkylated hydrazide (8k) can also be prepared more directly by reacting the aldehyde (8 g) with an already N-alkylated hydrazine derivative like compound 3d from scheme 3.
The intermediates above, such as the epoxide 8d and alcohol 8e where R1 is as defined above are novel compounds and constitute another aspect of the invention.
If desired the hydroxy group of compound (8k) can be converted to a fluoride or a primary or secondary amine thus providing compounds according to general formula I wherein n is 1, X is H, E is N and L is F, NHC1-C3alkyl or N(C1-C3alkyl)2, as shown in scheme 9 below.

Reaction of alcohol 8k with a suitable fluorinating agent such as DAST or Deoxofluor or the like in a solvent like dichloromethane as described e.g. by Singh, R. P. and Shreve, J. M. in Synthesis, 17, 1999, p. 2561-2578, yields the corresponding fluoro compound 9a. Alternatively, the hydroxy group of compound 8k can be transferred to an amine using any convenient method described in the literature. For example the Mitsunobu procedure can be used, i.e. reaction of the alcohol (8k) with an azodicarboxylate such as DIAD or the like in the presence of triphenylphosphine followed by displacement with a desired amine which provides the corresponding amino derivative (9b). An alternative route to the amine (9b) is by transformation of the hydroxy group into a leaving group such as a derivative of sulphonic acid like a mesylate, triflate, tosylate or the like by treatment with the appropriate sulphonylating agent in a solvent like for instance pyridine or dichloromethane optionally in the presence of triethylamine or the like, followed by displacement of the leaving group with a desired primary or secondary amine NH2C1-C3alkyl or NH(C1-C3alkyl)2. Alternatively, the leaving group can be displaced with azide, or the hydroxy group can be converted directly to an azide by use of an azide transfer agent like diphenyl phosphoryl azide (DPPA), subsequent reduction of the introduced azide to an amine, by for example triphenylphosphine optionally in the presence of a base like triethylamine provides compounds wherein L is NH2 whereas a reductive amination of the afforded amine with a desired aldehyde or ketone provides secondary or tertiary amines.
Dihydroxylated or difluorinated compounds wherein n is 1, E is N and X=L=OH or F in general formula I can be prepared as depicted in scheme 10.

The olefine derivative (10a) can be achieved from the alcohol (8f), prepared as described in scheme 8, by transforming the primary alcohol to a leaving group such as a mesylate or the like followed by an elimination reaction brought about for example by treatment with a base such as t.BuOK or DBU in a solvent like DMSO, DMF or dichloromethane optionally in the presence of a crown ether. The afforded unsaturated compound (10a) can then be epoxidized by treatment with a suitable oxidizing reagent such as mCPBA or BuOOK or the like in a solvent like dichloromethane to give the epoxide (10b). Opening of the epoxide with a desired hydrazide derivative as described in scheme 1 then yields the diol (10d). Alternatively, a dihydroxylation of the double bond in the olefin (10a) can be performed for example by treatment with an oxidizing system such as OsO4 and NMMO or the like which gives the triol (10c). Transformation of the primary alcohol into a leaving group as described above followed by a substitution reaction with the desired hydrazide derivative provides the dihydroxy hydrazide (10d). If desired, the two hydroxy groups can then be converted to fluorides by fluorination procedures known in the art for instance by using a fluorinating reagent such as DAST, Deoxofluor or the like as described by Rajendra et al. in Synthesis 17, 2002, p. 2561-2578, to give the difluorohydrazide (10e).
Compounds according to general formula I wherein n is 1, E is N, X is OH and L is F, NH(C1-C3alkyl) or N(C1-C3alkyl)2 can be prepared as exemplified in scheme 11.

Transformation of the primary alcohol 8f, prepared as described in scheme 8, to a leaving group such as a derivative of sulphonic acid like a mesylate, triflate, tosylate or the like by treatment with the appropriate sulphonylating agent in a solvent like for instance pyridine or dichloromethane optionally in the presence of triethylamine or the like, followed by an elimination reaction brought about for instance by treatment with a base such as t.BuOK or DBU in a solvent like DMSO, DMF or dichloromethane optionally in the presence of a crown ether, or any other suitable elimination conditions. The hydroxy group of the afforded unsaturated compound (11b) can then be converted to a fluoride for example by reaction with a suitable fluorinating agent such as DAST or Deoxofluor or the like in a solvent like dichloromethane as described e.g. by Singh, R. P. and Shreve, J. M. in Synthesis, 17, 1999, p. 2561-2578, which yields the corresponding fluoro compound (11c). Alternatively, the hydroxy group of compound (11b) can be transferred to an amine using any convenient method described in the literature. For example the Mitsunobu procedure can be used, i.e. reaction of the alcohol (11b) with an azodicarboxylate such as DIAD or the like in the presence of triphenylphosphine followed by displacement with a desired amine which provides the corresponding amino derivative (11c). An alternative route to the amine (11c) is by transformation of the hydroxy group into a leaving group such as a derivative of sulphonic acid like a mesylate, triflate, tosylate or the like by treatment with the appropriate sulphonylating agent in a solvent like for instance pyridine or dichloromethane optionally in the presence of triethylamine or the like, followed by displacement of the leaving group with a desired primary or secondary amine NH2C1-C3alkyl or NH(C1-C3alkyl)2. Alternatively, the leaving group can be displaced with azide, or the hydroxy group can be converted directly to an azide by use of an azide transfer agent like diphenyl phosphoryl azide (DPPA), subsequent reduction of the introduced azide to an amine, by for example triphenylphosphine optionally in the presence of a base like triethylamine provides compounds wherein L is NH2 whereas a reductive amination of the afforded amine with a desired aldehyde or ketone provides secondary or tertiary amines.
Further treatment of the olefinic compound (11c) as described for compound 10a in scheme 10, i.e. either epoxidation of the double bond followed by reaction with the desired hydrazide derivative or dihydroxylation of the double bond followed by mesylation, substitution and finally reaction with the desired hydrazide derivative, provides the hydrazide derivative (11d). If desired, the hydroxy group of compound 11d can be converted to a fluoride by treatment with DAST or the like, as previously described thus providing compounds according to general formula I wherein X is F.
A route to compounds according to general formula I wherein n is 1, E is N, X is F and L is OH, F, NH(C1-C3alkyl) or N(C1-C3alkyl)2 is illustrated in scheme 12.

Opening of the epoxide (10b) by use of a fluorinating agent such as (HF)x/pyridine as described i.a. by Baklouti, A. et al. in Synthesis 1999, p. 85-89, or (i-PrO)2TiF2-ET4NF-nHF as described by Hara, S. et al. in Tetrahedron 55, 1999, p. 4947-4954 or any other suitable fluorinating agent provides the fluorohydrine (12a). Transformation of the primary hydroxy group into a leaving group such as a derivative of sulphonic acid like a mesylate, triflate, tosylate or the like by treatment with the appropriate sulphonylating agent in a solvent like for instance pyridine or dichloromethane optionally in the presence of triethylamine or the like, followed by reaction with a desired hydrazide derivative then gives the hydrazide (12b). If desired, the hydroxy group of the hydrazide (12b) can be converted to a fluoride by treatment with DAST or the like thus providing compounds according to general formula I wherein L is F, or the hydroxy group can be converted to an amine for example by way of a Mitsunobu reaction by treatment with the desired amine in the presence of DIAD or the like or by transformation of the hydroxy group to an azide followed by reduction of the azide to an amine, thus providing compound according to general formula I wherein L is NH2 or the afforded amine can be reacted in a reductive amination with a desired aldehyde or ketone as previously described, thus providing compounds according to general formula I wherein L a substituted amine.
Compounds according to general formula I wherein L is F, X is C1-C3alkyl, n is 1 and E is N can be prepared as illustrated in scheme 13.

Epoxidation of the olefinic compound (11c), prepared as described in scheme 11, by reaction with a suitable oxidizing agent such as mCPBA or t.BuOOK or the like in a solvent like dichloromethane provides epoxide (13a). The alkylated compound (13b) can the be achieved by regioselective opening of the epoxide effected for example by using an aluminium reagent such as (alkyl)2AlOAlalkyl or (alkyl)3Al in the presence of water in a solvent like dichloromethane as described i.a. by Maruoka, K. et al. in Tetrahedron Lett., 40, 1999, p. 5369-5372 or by using an alkyltitanium reagent as described by Tanaka, T. et al. in Tetrahedron Lett. 45, 2004, p. 75-78. Conversion of the formed primary alcohol to a leaving group such as a halide like chlorine, bromine or iodine or to a derivative of sulphonic acid such as a mesylate, triflate, tosylate or the like by treatment with the appropriate sulphonylating agent in a solvent like for instance pyridine or dichloromethane optionally in the presence of triethylamine or the like, followed by reaction with a desired hydrazide derivative optionally in the presence of a base like Et3N, t.BuOK or the like then gives the hydrazide (13d).
The synthesis of hydrazides (8 h) are described in the literature, se for example J. Med. Chem. 1998, 41, p. 3387, a general example thereof is shown in scheme 14.

Commercially available t-butyl carbazate (14a) can be coupled to an acid (14b) wherein A″ is as defined above, in a peptide coupling reaction using standard procedure to give the corresponding Boc protected hydrazide (14c). Removal of the Boc group using standard conditions like acidic treatment, for example with TFA in dichloromethane provides the unprotected hydrazide (8h).
Compounds according to formula I wherein E is CH and n is 0 or 1, can be prepared as exemplified in scheme 15.

The aldehyde (15b) can be prepared by subjecting a desired amino acid or homo amino acid derivative (15a) to N,O-dimethylhydroxylamine under peptide coupling conditions such as in the presences of EDAC, HOBT, triethylamine or the like, followed by reduction of the formed Weinreb amide with a reducing agent like LiAlH4. Coupling of the formed aldehyde with a phosphonate (15c) in a Horner-Emmons reaction as described for example by A. Nadine et al. in Bioorg. Med. Chem. Lett., 2003, 13, 37-41, provides alkene (15e). The double bond can then be epoxidized using for instance mCPBA and the formed epoxide (15f) opened reductively by hydrogenation in the presence of a catalyst like Pt(IV)O as described in scheme 8. Subsequent coupling of the remaining fragments, A″ and A′ defined as for general formula I, using standard peptide coupling methods, i.e. removal of the boc group, coupling of the acid A″COOH followed by hydrolysis of the ester group and coupling of the amine A′-NH2 yields the amide (15h). Compounds wherein A″ is according to formula (VI) are conveniently prepared by reacting the N-unprotected derivative of (15g) with an activated carbonate or chloroformate of the desired derivative, prepared as described in scheme 4, instead of with the acid A″-COOH.
The hydroxy group of compound (15h) can be converted to a fluoride or a primary or secondary amine thus providing compounds according to general formula I wherein X is H, E is CH and L is F, NHC1-C3alkyl or N(C1-C3alkyl)2, as shown in scheme 16 below.

Reaction of alcohol (15h) with a suitable fluorinating agent such as DAST or Deoxofluor or the like in a solvent like dichloromethane as described e.g. by Singh, R. P. and Shreve, J. M. in Synthesis, 17, 1999, p. 2561-2578, yields the corresponding fluoro compound (16a). Alternatively, the hydroxy group of compound 15h can be transferred to an amine using any convenient method described in the literature. For example the Mitsunobu procedure can be used, i.e. reaction of the alcohol (15h) with an azodicarboxylate such as DIAD or the like in the presence of triphenylphosphine followed by displacement with a desired amine which provides the corresponding amino derivative (16b). An alternative route to the amine (16b) is by transformation of the hydroxy group into a leaving group such as a derivative of sulphonic acid like a mesylate, triflate, tosylate or the like by treatment with the appropriate sulphonylating agent in a solvent like for instance pyridine or dichloromethane optionally in the presence of triethylamine or the like, followed by displacement of the leaving group with a desired primary or secondary amine NH2C1-C3alkyl or NH(C1-C3alkyl)2. Alternatively, the leaving group can be displaced with azide, or the hydroxy group can be converted directly to an azide by use of an azide transfer agent like diphenyl phosphoryl azide (DPPA), subsequent reduction of the introduced azide to an amine, by for example triphenylphosphine optionally in the presence of a base like triethylamine provides compounds wherein L is NH2 whereas a reductive amination of the afforded amine with a desired aldehyde or ketone provides secondary or tertiary amines.
Dihydroxylated or difluorinated compounds wherein E is CH and X=L=OH or F and n is 0 or 1 in general formula I can be prepared as depicted in scheme 17.

Hydrolysis of the epoxide (15f) obtained from scheme 15 can be performed by using any convenient procedure known in the art, like for example subjection of the epoxide to acidic conditions such as treatment with a protic acid for example diluted perchloric acid, sulphuric acid or formic acid or with a Lewis acid such as BiCl3 in a solvent like tetrahydrofuran or the like, which gives the diol (17a). Subsequent coupling of the acid A″-COOH and the amine A′-NH2 as described in scheme 15 gives the dihydroxy amid (17b). If desired, the two hydroxy groups can then be converted to fluorides by using a fluorinating reagent such as DAST, Deoxofluor or the like to give the difluorohydrazide (17c).
A route to compounds according to general formula I wherein E is CH, X is OH, L is F and n is 0 or 1 is illustrated in scheme 18.

Opening of the epoxide (15f) by use of a fluorinating agent such as (HF)x/pyridine as described i.a. by Baklouti, A. et al. in Synthesis 1999, p. 85-89 or (i-PrO)2TiF2-ET4NF-nHF as described by Hara, S. et al. in Tetrahedron 55, 1999, p. 4947-4954 or any other suitable fluorinating agent provides the fluorohydrine (18a). Subsequent coupling, in any suitable order, of the acid A″-COOH and the amine A′-NH2 as described in scheme 7 gives the fluorohydrine (18d). If desired, the hydroxy group of any of compounds 18a, 18b or 18c can be converted to a fluoride by treatment with DAST or the like, as previously described, thus providing an alternative route to compounds according to general formula I wherein X and L are F.
Compounds according to general formula I wherein E is CH, L is OH, F, NHC1-C3alkyl or N(C1-C3alkyl)2, X is C1-C3alkyl and n is 0 or 1 can be prepared as illustrated in scheme 19.

Alkylation of the epoxide (15f) prepared ad described in scheme 15, using an organocopper reagent such as a lithium dialkylcuprate in a solvent like diethyl ether or THF or the like provides the alkylated compound (19a). Coupling of the acid A″-COOH and the amine A′-NH2, in any suitable order, as described in scheme 15 then gives the hydrazide derivative (19b). If desired, the hydroxy group of compound 19b can be converted to a fluoride by treatment with DAST or the like thus providing compounds according to general formula I wherein L is F, or the hydroxy group can be converted to an amine for example by way of a Mitsunobu reaction by treatment with the desired amine in the presence of DIAD or the like or by transformation of the hydroxy group to an azide followed by reduction of the azide to an amine, thus providing compounds according to general formula I wherein L is NH2 or the afforded amine can be reacted in a reductive amination with a desired aldehyde or ketone as previously described, thus providing compounds according to general formula I wherein L a substituted amine.
An alternative route to compounds wherein E is CH and n is 1 is shown in scheme 20.

Bromoderivative (20b) can be prepared from a suitable alkylated malonate derivative (20a), by a hydrolysation-reduction procedure followed by transformation of the formed primary alcohol to a bromide as described by Jew et al. in Heterocycles, 46, 1997, p. 65-70. Alkylated malonate derivatives are available either commercially or by alkylation of diethyl malonate with a desired alkylating agent according to literature procedures well known by the skilled person. The tertiary alcohol of the afforded bromoderivative (20b) can optionally be protected for instance as an acetate effected by treatment with acetic anhydride in pyridine or the like and subsequently coupled to a copper-zinc reagent (20d) prepared from a natural or non-natural amino acid, as described by Dudu et al. in Tetrahedron 50, 1994, p. 2415-2432 to give (20e). The remaining fragments, A″ and A′ defined as for general formula I, can then be introduced as described in scheme 15.
Substitution of the R2 group of any of the above described compounds with a desired group using any suitable method known from the literature can be performed at any convenient stage of the synthesis. A method wherein a heteroaryl group is added to an aryl group is exemplified in scheme 21.

The aryl group of compound (21a) can be substituted with for example an aryl or heteroaryl group such as a pyridyl group by reacting the tri-n-butyltin derivative of the desired substituent in a coupling reaction using a palladium(0) reagent such as Pd(PPh3)2Cl2 or the like in the presence of CuO in a solvent like dimethylformamide at an elevated temperature effected for instance by heating with microwaves.
It should be recognized that the strategy described in scheme 21 is not restricted only to pyridyl groups but is also applicable to other, optionally substituted, alkyl, aryl or heteroaryl groups. It should also be recognized that other methods, many of which are extensively described in the literature, may be used for the substitution of the R2-group.
A general route to compounds according to formula I wherein n is 2 and E is N is shown in scheme 22.

The two hydroxy groups of a desired 3-substituted 2-hydroxypropionic acid (22a) can be protected as a cyclic acetal by reacting the acid with a suitable acetalisation reagent such as 2,2-dimethoxypropane or 2-methoxypropene under acidic conditions achieved for example by the presence of a catalytic amount of pyridinium tosylate (PPTS), pTS, CSA or the like, which gives the cyclic acetal (22b). A subsequent Michael addition of methyl acrylate to the afforded acetal in the presence of a base such as LDA or the like then gives the α-alkylated compound (22c). Hydrolysation of the acetal and ring closure of the afforded intermediate alcohol, effected by treatment with an acid such as TFA at an elevated temperature gives the lactone (22d). Coupling of the amine A′-NH2 using standard peptide coupling conditions, such as using reagents like EDAC, HOBt and optionally a base such as triethylamine or the like and subsequent reductive opening of the lactone using a reducing agent such as LiBH4 or the like provides the diol (22f). The hydrazide derivative (22g) can then be achieved by using any of the methods previously described. For example the oxidation-reductive amination sequence described i.a. in scheme 8 can be used, i.e. the primary hydroxy group is oxidised to an aldehyde using any convenient oxidising agent like for instance Dess-Martin periodinane, followed by a reductive amination reaction with the desired hydrazide derivative in the presence of a suitable reducing agent like Na(OAc)3BH or the like. Alternatively, the hydrazide moiety can be introduced by a displacement reaction as described i.a. in scheme 10, i.e. the primary alcohol is transferred to a leaving group such as a mesylate or the like whereafter the leaving group is displaced by the desired hydrazide derivative. If desired, the hydroxy substituent of hydrazide (22g) can be converted to an amine or a fluoro substituent using any of the previously described strategies thus providing compounds according to general formula (I) wherein L is F, NH2, NHC1-C6alkyl or N(C1-C6alkyl)2, X is H, n is 2 and E is N.
As will be appreciated by a person skilled in the field of organic synthesis, the synthetic steps in the preparation of compounds according to formula I can be performed in another order where appropriate. For example, the substituent —CH2—R2 of the hydrazide nitrogen of compounds wherein E is N, can be introduced by using a substituted hydrazide derivative as illustrated in scheme 1, or alternatively an unsubstituted or optionally temporarily N-protected hydrazide derivative can be used and the N-substituent introduced afterwards as illustrated in scheme 8. It should also be realized that the introduction of the amino and acid derivatives e.g. in scheme 18 and 19 can be performed in the reversed order, i.e. the acid A″-COOH is coupled prior to the amine A′-NH2.
Any functional groups present on any of the constituent compounds used in the preparation of the compounds of the invention are appropriately protected where necessary. For example functionalities on the natural or non-natural amino acids are typically protected as is appropriate in peptide synthesis. Those skilled in the art will appreciate that the selection and use of appropriate protecting groups depend upon the reaction conditions. Suitable protecting groups are described in Greene, “Protective Groups in Organic Synthesis”, John Wiley & Sons, New York (1981) and “The Peptides: Analysis, Synthesis, Biology”, Vol. 3, Academic Press, New York (1981), the disclosure of which are hereby incorporated by reference.